1. Field of the Invention
The present invention generally refers to a method and a system for sensing a body temperature of animals and/or for measuring a parameter related to physical activity of animals, and furthermore to a use of such a system. The method and the system are preferably used in observational screening and particularly preferably in drug screening.
2. Description of the Background Art
In different fields, measuring the body temperature and/or a parameter related to physical activity of animals may be of interest. As an example, this is the case in screening methods, particularly in drug screening methods. Here, researchers may want to measure the response of one of more animals to a certain substance or to a certain condition. The response may be manifested in a change of body temperature and/or physical activity.
As an example, several pathophysiological conditions are typically associated with changes in body temperature. This has been observed in immunologic and infectious diseases and in association with pharmacologic or toxic effects and is basically a sign of inflammation. Also in allergies, especially in the severest form of allergy, i.e. the anaphylactic shock, body temperature is affected. This setting can be mimicked in mouse anaphylaxis studies where body temperature is usually evaluated by rectal measurements. Further, the physical activity of the animals may be altered as diseased animals are often demobilized by impaired breathing or lowering of blood pressure which is mostly recorded by hand-held counting machines by the scientist. Monitoring of rearing and climbing of animals, e.g. mice, is, moreover, a tool typical for behavioural sciences, and the phenomena are similar to events seen in human patients. Evaluation of the body temperature by rectal measurement and monitoring of physical activity are routinely made in industrial and academic labs engaged in screening studies and in proof of concept studies for therapeutic or prophylactic medications.
In particular with regard to allergies, the change in physical activity may be caused as follows. In allergy IgE immunoglobulins are disease eliciting. They are bound by IgE receptors on inflammatory effector cells. Upon consecutive antigen contact, IgE crosslinking occurs and leads to release of mediators causing allergic inflammation. In case of rapid entrance of potent allergens, the allergens can reach multiple IgE-armed effector cells making the event accelerate to so-called anaphylactic shock. Thereby, a dramatic centralisation of blood into the central vital organs occurs due to adrenergic stimulus. As a consequence, in animals a rapid drop of blood pressure occurs making them dizzy and sometimes rendering collapse. In mice the anaphylactic reaction is accompanied by reduction of body activity, meaning that mice which normally rear 10-20 times per minute cower down and stop motioning. This parameter is often used as readout for disease intensity in anaphylaxis or asthma and counts are done manually.
Further, the centralization of blood leads to a cooling down of body temperature by several degrees. This phenomenon is monitored in animal experiments by rectal temperature measurements. This is a tedious and time consuming procedure and, is an additional stress factor for the animals.
In these screening methods, trained personnel use rectal temperature measurement and count how often the animals rear within a time frame. In particular with regard to the temperature measurement, the personnel come into direct contact with the animals, thereby causing additional stress to the animals which may alter their body temperature. Further and with particular regard to drug testing, it may be problematic that the personnel come into direct contact with animals carrying potentially hazardous infections. Additionally, with this method, only few data points in time can be recorded. As a consequence, the current practice is a time-consuming, costly and inaccurate method, requiring tedious manual measurements, which potentially alters the results and exposes the personnel to certain risks.